1. Field of the Invention
The present invention relates, generally, to an inorganic electroluminescent diode and a method of fabricating the same, and more particularly, to an inorganic electroluminescent diode, comprising a semiconductor nanocrystal layer formed of inorganic material, an electron transport layer or a hole transport layer formed on the semiconductor nanocrystal layer using amorphous inorganic material, and a hole transport layer or an electron transport layer formed beneath the semiconductor nanocrystal layer using inorganic material, and to a method of fabricating such an inorganic electroluminescent diode.
2. Description of the Related Art
Various attempts have been made to solve a problem of a decrease in the lifetime of an organic electroluminescent diode due to the degradation of organic luminescent material. In this regard, U.S. Patent Application Publication No. 2004/0023010 discloses an electroluminescent diode, comprising a luminescent layer formed of inorganic quantum dots, and an electron transport layer and a hole transport layer respectively in the form of organic thin films.
In the electroluminescent diode of the above patent, organic/inorganic interfacial defects may occur because the organic thin film layers are in contact with the inorganic luminescent layer, and thus, stability is decreased upon operation of the device. Further, since it is easy for the organic thin film layer to degrade or deteriorate due to air or moisture, an additional encapsulation process should be performed to encapsulate the organic thin film layer, or the diode should be fabricated in a chamber having no oxygen or nitrogen.
Further, U.S. Pat. No. 6,797,412 discloses an electroluminescent diode composed completely of inorganic material, comprising a luminescent layer formed of a clad quantum dot thin film, a hole transport layer formed of a p-type semiconductor, and an electron transport layer formed of an n-type semiconductor.
In the electroluminescent diode of the aforementioned reference, a p-doped silicon layer and a silicon layer are formed on a substrate, after which the hole transport layer, the quantum dot thin film, and the electron transport layer are sequentially formed thereupon. Upon formation of the electroluminescent diode having the above structure, the n-type semiconductor layer is deposited at high temperatures on the quantum dot thin film. As a result, the quantum dot of the quantum dot thin film may lose its inherent quantum confinement effect due to the high temperature upon crystal growth, undesirably decreasing the luminescent efficiency and deforming the structure of the quantum dot thin film.